// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_PUBLIC_BROWSER_PRESENTATION_SERVICE_DELEGATE_H_
#define CONTENT_PUBLIC_BROWSER_PRESENTATION_SERVICE_DELEGATE_H_

#include <map>
#include <memory>
#include <string>
#include <vector>

#include "base/callback.h"
#include "content/common/content_export.h"
#include "content/public/common/presentation_connection_message.h"
#include "content/public/common/presentation_session.h"
#include "third_party/WebKit/public/platform/modules/presentation/presentation.mojom.h"

class GURL;

namespace content {

class PresentationScreenAvailabilityListener;

using PresentationSessionStartedCallback = base::Callback<void(const PresentationSessionInfo&)>;
using PresentationSessionErrorCallback = base::Callback<void(const PresentationError&)>;

// Param #0: a vector of messages that are received.
// Param #1: tells the callback handler that it may reuse strings or buffers
//           in the messages contained within param #0.
using PresentationConnectionMessageCallback = base::Callback<void(
    const std::vector<std::unique_ptr<content::PresentationConnectionMessage>>&,
    bool)>;

struct PresentationConnectionStateChangeInfo {
    explicit PresentationConnectionStateChangeInfo(
        PresentationConnectionState state)
        : state(state)
        , close_reason(PRESENTATION_CONNECTION_CLOSE_REASON_CONNECTION_ERROR)
    {
    }
    ~PresentationConnectionStateChangeInfo() = default;

    PresentationConnectionState state;

    // |close_reason| and |messsage| are only used for state change to CLOSED.
    PresentationConnectionCloseReason close_reason;
    std::string message;
};

using PresentationConnectionStateChangedCallback = base::Callback<void(const PresentationConnectionStateChangeInfo&)>;

using PresentationConnectionPtr = blink::mojom::PresentationConnectionPtr;
using PresentationConnectionRequest = blink::mojom::PresentationConnectionRequest;

using ReceiverConnectionAvailableCallback = base::Callback<void(const content::PresentationSessionInfo&,
    PresentationConnectionPtr,
    PresentationConnectionRequest)>;

// Base class for ControllerPresentationServiceDelegate and
// ReceiverPresentationServiceDelegate.
class CONTENT_EXPORT PresentationServiceDelegate {
public:
    // Observer interface to listen for changes to PresentationServiceDelegate.
    class CONTENT_EXPORT Observer {
    public:
        // Called when the PresentationServiceDelegate is being destroyed.
        virtual void OnDelegateDestroyed() = 0;

    protected:
        virtual ~Observer() { }
    };

    virtual ~PresentationServiceDelegate() { }

    // Registers an observer associated with frame with |render_process_id|
    // and |render_frame_id| with this class to listen for updates.
    // This class does not own the observer.
    // It is an error to add an observer if there is already an observer for that
    // frame.
    virtual void AddObserver(int render_process_id,
        int render_frame_id,
        Observer* observer)
        = 0;

    // Unregisters the observer associated with the frame with |render_process_id|
    // and |render_frame_id|.
    // The observer will no longer receive updates.
    virtual void RemoveObserver(int render_process_id, int render_frame_id) = 0;

    // Resets the presentation state for the frame given by |render_process_id|
    // and |render_frame_id|.
    // This unregisters all screen availability associated with the given frame,
    // and clears the default presentation URL for the frame.
    virtual void Reset(int render_process_id, int render_frame_id) = 0;
};

// An interface implemented by embedders to handle Presentation API calls
// forwarded from PresentationServiceImpl.
class CONTENT_EXPORT ControllerPresentationServiceDelegate
    : public PresentationServiceDelegate {
public:
    using SendMessageCallback = base::Callback<void(bool)>;

    // Registers |listener| to continuously listen for
    // availability updates for a presentation URL, originated from the frame
    // given by |render_process_id| and |render_frame_id|.
    // This class does not own |listener|.
    // Returns true on success.
    // This call will return false if a listener with the same presentation URL
    // from the same frame is already registered.
    virtual bool AddScreenAvailabilityListener(
        int render_process_id,
        int render_frame_id,
        PresentationScreenAvailabilityListener* listener)
        = 0;

    // Unregisters |listener| originated from the frame given by
    // |render_process_id| and |render_frame_id| from this class. The listener
    // will no longer receive availability updates.
    virtual void RemoveScreenAvailabilityListener(
        int render_process_id,
        int render_frame_id,
        PresentationScreenAvailabilityListener* listener)
        = 0;

    // Sets the default presentation URLs for frame given by |render_process_id|
    // and |render_frame_id|. When the default presentation is started on this
    // frame, |callback| will be invoked with the corresponding
    // PresentationSessionInfo object.
    // If |default_presentation_urls| is empty, the default presentation URLs will
    // be cleared and the previously registered callback (if any) will be removed.
    virtual void SetDefaultPresentationUrls(
        int render_process_id,
        int render_frame_id,
        const std::vector<GURL>& default_presentation_urls,
        const PresentationSessionStartedCallback& callback)
        = 0;

    // Starts a new presentation session. The presentation id of the session will
    // be the default presentation ID if any or a generated one otherwise.
    // Typically, the embedder will allow the user to select a screen to show
    // one of the |presentation_urls|.
    // |render_process_id|, |render_frame_id|: ID of originating frame.
    // |presentation_urls|: Possible URLs for the presentation.
    // |success_cb|: Invoked with session info, if presentation session started
    // successfully.
    // |error_cb|: Invoked with error reason, if presentation session did not
    // start.
    virtual void StartSession(
        int render_process_id,
        int render_frame_id,
        const std::vector<GURL>& presentation_urls,
        const PresentationSessionStartedCallback& success_cb,
        const PresentationSessionErrorCallback& error_cb)
        = 0;

    // Joins an existing presentation session. Unlike StartSession(), this
    // does not bring a screen list UI.
    // |render_process_id|, |render_frame_id|: ID for originating frame.
    // |presentation_urls|: Possible URLs of the presentation.
    // |presentation_id|: The ID of the presentation to join.
    // |success_cb|: Invoked with session info, if presentation session joined
    // successfully.
    // |error_cb|: Invoked with error reason, if joining failed.
    virtual void JoinSession(
        int render_process_id,
        int render_frame_id,
        const std::vector<GURL>& presentation_urls,
        const std::string& presentation_id,
        const PresentationSessionStartedCallback& success_cb,
        const PresentationSessionErrorCallback& error_cb)
        = 0;

    // Closes an existing presentation connection.
    // |render_process_id|, |render_frame_id|: ID for originating frame.
    // |presentation_id|: The ID of the presentation to close.
    virtual void CloseConnection(int render_process_id,
        int render_frame_id,
        const std::string& presentation_id)
        = 0;

    // Terminates an existing presentation.
    // |render_process_id|, |render_frame_id|: ID for originating frame.
    // |presentation_id|: The ID of the presentation to terminate.
    virtual void Terminate(int render_process_id,
        int render_frame_id,
        const std::string& presentation_id)
        = 0;

    // Listens for messages for a presentation session.
    // |render_process_id|, |render_frame_id|: ID for originating frame.
    // |session|: URL and ID of presentation session to listen for messages.
    // |message_cb|: Invoked with a non-empty list of messages whenever there are
    // messages.
    virtual void ListenForConnectionMessages(
        int render_process_id,
        int render_frame_id,
        const content::PresentationSessionInfo& session,
        const PresentationConnectionMessageCallback& message_cb)
        = 0;

    // Sends a message (string or binary data) to a presentation session.
    // |render_process_id|, |render_frame_id|: ID of originating frame.
    // |session|: The presentation session to send the message to.
    // |message|: The message to send. The embedder takes ownership of |message|.
    //            Must not be null.
    // |send_message_cb|: Invoked after handling the send message request.
    virtual void SendMessage(
        int render_process_id,
        int render_frame_id,
        const content::PresentationSessionInfo& session,
        std::unique_ptr<PresentationConnectionMessage> message,
        const SendMessageCallback& send_message_cb)
        = 0;

    // Continuously listen for state changes for a PresentationConnection in a
    // frame.
    // |render_process_id|, |render_frame_id|: ID of frame.
    // |connection|: PresentationConnection to listen for state changes.
    // |state_changed_cb|: Invoked with the PresentationConnection and its new
    // state whenever there is a state change.
    virtual void ListenForConnectionStateChange(
        int render_process_id,
        int render_frame_id,
        const PresentationSessionInfo& connection,
        const PresentationConnectionStateChangedCallback& state_changed_cb)
        = 0;

    // Connect |controller_connection| owned by the controlling frame to the
    // offscreen presentation represented by |session|.
    // |render_process_id|, |render_frame_id|: ID of originating frame.
    // |controller_connection|: Pointer to controller's presentation connection,
    // ownership passed from controlling frame to the offscreen presentation.
    // |receiver_connection_request|: Mojo InterfaceRequest to be bind to receiver
    // page's presentation connection.
    virtual void ConnectToOffscreenPresentation(
        int render_process_id,
        int render_frame_id,
        const PresentationSessionInfo& session,
        PresentationConnectionPtr controller_connection_ptr,
        PresentationConnectionRequest receiver_connection_request)
        = 0;
};

// An interface implemented by embedders to handle
// PresentationService calls from a presentation receiver.
class CONTENT_EXPORT ReceiverPresentationServiceDelegate
    : public PresentationServiceDelegate {
public:
    // Registers a callback from the embedder when an offscreeen presentation has
    // been successfully started.
    // |receiver_available_callback|: Invoked when successfully starting a
    // offscreen presentation session.
    virtual void RegisterReceiverConnectionAvailableCallback(
        const content::ReceiverConnectionAvailableCallback&
            receiver_available_callback)
        = 0;
};

} // namespace content

#endif // CONTENT_PUBLIC_BROWSER_PRESENTATION_SERVICE_DELEGATE_H_
